How to shutdown my Xfinity internet and voice service.

I am dropping Xfinity internet/voice after all these years and want to ensure that I do this correctly. I *think* as soon as the new internet is hooked up, I need to take the Xfinity gateway device to an Xfinity store and turn it in, letting them know that I am cancelling the 2 services. The workers at the store are able to update my account to Include only the Xfinity TV service without any other Comcast processing needed. I also need to work with the new voice provider to ensure I get my phone number deactivated on Xfinity and activated on the new network. This is something the new voice provider should do by working with Xfinity. I can continue to use my comcast email address by logging into my comcast account within a week of dropping Xfinity internet.

Please let me know if I am missing ANYTHING that might result in a problem with this transition of my Internet and Voice services. I want this to go as smoothly as possible!

Thank you